Optically active polymer: synthesis and characterization of new optically active poly (hydrazide-imide)s incorporating L- leucine

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdol Reza Hajipour ◽  
Saeed Zahmatkesh ◽  
Arnold E. Ruoho

AbstractThis paper deals with the polycondensation between a chiral diacyl chloride (N,N′-Pyromelliticdiimido-di-L-leucine chloride) and six different dihydrazides. The corresponding poly (hydrazide-imide)s which have been obtained in quantitative yields are moderately soluble in polar aprotic solvents, have good thermal stability and optical activity. The synthetic compounds have been characterized by IR, UV and 1H NMR spectroscopy, elemental analysis and specific rotation. The thermal properties of the polymers (10 and 15) have been studied by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC).

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
J. L. Feng ◽  
C. Y. Yue ◽  
K. S. Chian

AbstractThis project aims to develop and characterize a series of bismaleimide (BMI) polymers based on maleic anhydride and aliphatic-ether diamines. The effects of varying the chain length of aliphatic-ether diamines on the resultant bismaleimide systems were evaluated so that their suitability for microelectronics applications could be evaluated. The synthetic reaction and properties of the bismaleimide materials were investigated using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermo- Gravimetric Analysis (TGA), Dielectric Thermal Analysis (DEA) and rheometry. Results showed that thermal, dielectric and rheological properties were all affected by the main chain length of BMI. The magnitude of the dielectric constant at 100 kHz increases with the increasing chain length. The curing peak temperature, curing heat and degradation temperature of BMI, all decrease with the increasing chain length.


2013 ◽  
Vol 652-654 ◽  
pp. 490-494
Author(s):  
Bo Shi ◽  
Liang Liang ◽  
Bo Lin ◽  
Min Hua Qi

Using dendritic bromide poly (benzyl ether), G2-Br, as macroinitiator, dendritic-linear polymer (G2-PS-NHSO3Na) was obtained via atom transfer radical polymerization and nucleophilic substitution of G2-PS-Br. G2-PS-NHSO3Na was constructed on cationic silica by both electrostatic attraction and steric effort coming from dendritic block of G2-PS-NHSO3Na. 1H-NMR and differential scanning calorimetry were used to characterize the structure and thermal behavior of G2-PS-NHSO3Na; thermo-gravimetric analysis and TEM were applied to analysis the assembly amount of G2-PS-NHSO3Na and the dispersibility of silica before and after assembly. The results show that G2-PS-NHSO3Na can be synthesized successfully and has exact structure; it can be constructed on cationic silica with 27% assembly amount; the aggregation of silica can be prevented effectively by the dendritic-linear brushes, but the molecular weight of linear segment and the generation of dendritic block will influence the assembly behavior and the amount of the dendritic-linear brushes.


Author(s):  
Abdel-Hamid I. Mourad ◽  
Omar G. Ayad ◽  
Ashfakur Rahman ◽  
Ali Hilal-Alnaqbi ◽  
Basim I. Abu-Jdayil

This work is concerned with the synthesis and characterization of Multi-Walled Carbon Nanotube (MWCNT) reinforced Kevlar KM2Plus composites with various MWCNT contents (0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 wt. %), by the wet lay-up technique. These samples were experimentally investigated for their thermo-mechanical properties using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), tensile testing and three-point bending techniques. The mechanical properties showed remarkable improvement with increasing MWCNT wt.% up to certain content. The results revealed that the addition of MWCNT fillers has no significant effect on the thermal stability of the composites.


2011 ◽  
Vol 695 ◽  
pp. 45-48
Author(s):  
Dong Wan Seo ◽  
Young Don Lim ◽  
Soon Ho Lee ◽  
Md. Monirul Islam ◽  
Hyun Mi Jin ◽  
...  

Poly(ethersulfone)s carrying pendant sulfonated imide side group. The first step in the preparation involved nitration of poly(ethersulfone) (ultrason®-S6010), with ammonium nitrate and trifluoroacetic anhydride resulting in the nitrated poly(ethersulfone) (NO2-PES). In the second step, the nitro groups on polymer were reacted with tin(II)chloride and sodium iodide as reducing agents for creating the amino poly(ethersulfone) (NH2-PES). The imide-poly(ethersulfone)s (IPES) were obtained by reaction of phthalic anhydride and the amino-poly(ethersulfone) with triethyl amine. The sulfonated imide-poly(ethersulfone)s (SIPES) were prepared by chlorosulfonic acid. The different degrees of sulfonated imide units of poly(ethersulfone) were successfully synthesized by an optimized condition. The Sulfonated imide-poly(ethersulfone)s (SIPES) were studied by FT-IR,1H-NMR spectroscopy and thermo gravimetric analysis(TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water. The ion exchange capacity (IEC) and proton conductivity of SIPES membranes were evaluated with increase of degree of sulfonation. The water uptake of synthesized SIPES membranes exhibit 30 ~ 65 % compared with 28 % of Nafion 211®. The SIPES membranes exhibit proton conductivities (25 °C) of 1.21 ~ 2.62´10-3S/cm compared with 3.37´10-3S/cm of Nafion 211®.


2007 ◽  
Vol 4 (2) ◽  
pp. 222-231 ◽  
Author(s):  
B. L. Hiran ◽  
Jyoti Chadhary ◽  
S. N. Paliwal ◽  
Suresh Meena ◽  
P. R. Chaudhary

This article describes the synthesis and characterization of homopolymer (H-BCPM) of N-[4-N'-(benzylamino-carbonyl) phenyl] maleimide (N-BACPMI) and copolymer (C-BCPM) of N-BACPMI withn-butyl acrylate (BA). The new monomer was synthesized fromp-aminobenzoic acid, maleic anhydride and benzylamine. The homopolymerization of N-BACPMI is initiated by free radical using AIBN in THF solvent at 65°C. Radical copolymerization of N-BACPMI with BA, initiated by AIBN, was performed in THF solvent using equimolar amount. Effect of the different free radical initiator AIBN, BPO and solventsp-Dioxane, THF, DMF and DMSO was studied. Homopolymer and Copolymer were characterized by intrinsic viscosity, solubility test, FT-IR,1H-NMR spectral analysis and elemental analysis. Thermal behaviour was studied by Thermo gravimetric analysis.


2009 ◽  
Vol 28 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Imelda Olivas-Armendariz ◽  
Perla E. García-Casillas ◽  
Alberto Martínez-Villafañe ◽  
Carlos A. Martinez-Pérez

In this work the synthesis and characterization of polyurethane (PU)-chitosan(CH) porous prepared by thermal induced phase separation (TIPS) is described, the obtained products were characterized by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC), evidence of the interaction between both polymers was acquired from infrared spectroscopy. The morphology of the scaffolds was studied by scanning electron microscopy also the mechanical properties were acquired. The results showed that the TIPS technique is appropriate for the production of PU-CH porous materials.


Author(s):  
X. S. Gama

In deciding the workable layout of any network an appropriate technology plays a major role and can improve accuracy and flexibility efficiently, if chosen and implemented in best possible way. The growth in the infrared applications has created a need for knowledge of its optical characteristics in the spectral region for the purpose of designing. Very little work is previously reported in natural oil doped PVA membranes. In this work, a simple attempt is made synthesize and characterize the wintergreen oil and basil oil doped PVA membranes. In investigation, basil oil and wintergreen oil doped PVA membranes were prepared and is made to characterize. The resulting membranes were characterized by Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WXAD), thermo-gravimetric analysis (TGA) and differential scanning Calorimetry (DSC).


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Zahmatkesh ◽  
Abdol Reza Hajipour

AbstractPyromellitic dianhydride (1) was reacted with L-leucine (2) to result in [N,N'-(pyromellitoyl)-bis-L-leucine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacid chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic bisphenols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31- 0.53 dl g-1. These polymers are optically active, thermally stable and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc and sulfuric acid. All of the above polymers were fully characterized by IR spectroscopy, 1H NMR spectroscopy, elemental analyses, specific rotation and thermal analyses. Some structural characterizations and physical properties of these optically active PEIs and Co-PEIs are reported.


2021 ◽  
pp. 1-8
Author(s):  
Ching-Cheng Huang

BACKGROUND: The biologic scaffolds derived from decellularized tissues and organs have been successfully developed in a variety of preclinical and/or clinical studies. OBJECTIVE: The new decellularized liver-regenerative 3D printing biomaterials were designed and prepared for cell-based liver therapies. METHODS: An extraction process was employed to remove the tissue and cellular molecules from porcine liver via pretreatment of supercritical fluid of carbon dioxide (ScCO2). Varying porosities of the decellularized liver tissues were created using papain-containing reagent treatments after ScCO2. RESULTS: The resulting liver-regenerative 3D printing biomaterials of decellularized liver collagen scaffolds were characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. CONCLUSIONS: The decellularized liver collagen scaffolds with good thermal stability (>150 °C) were obtained and employed as liver-regenerative 3D printing biomaterials for cell-based liver therapies.


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